.mian,
.mian .vm {
  min-height: 100%;
  padding-bottom: 3rem;
}
nav {
  position: fixed;
  bottom: 0px;
  width: 100%;
  border-top: 1px solid skyblue;
}
nav .item {
  display: block;
  height: 3rem;
  line-height: 3rem;
  text-align: center;
}
nav .item,
nav .item * {
  color: black;
}
nav .item.active * {
  color: #87ceeb;
}
header {
  position: relative;
}
header h3 {
  height: 2rem;
  margin-top: 0px;
  line-height: 2rem;
  background: skyblue;
}
header .back {
  position: absolute;
  top: 0px;
  left: 0px;
  height: 2rem;
  width: 2rem;
  font-size: 1.5rem;
  line-height: 2rem;
  color: white;
}
form {
  padding: 0rem 0.4rem;
}
form .btn-block + .btn-block {
  margin-top: 0.7rem;
}
